This invention relates to the area of smart cards, more particularly smart cards designed to be installed in mobile or portable devices, such as for example smart phones, comprising elements managed by different standardised protocols, which elements can be fixed (welded) or removable.
Portable devices are becoming ever more multifunctional so as to allow the management of a series of applications from the same device. For example, these new applications relate to near-field contactless communication, which may be used for contactless payment or for season tickets such as in public transport, where the portable device acts as a transponder and interacts with a dedicated external reader.
Besides, it is obvious that these applications need to be made secure. To that end, secure smart card components are used and installed in the telephone; they contain the secure elements for the different applications.
Besides, means are required to allow communication between the elements of the different applications, to allow the proper working of those applications. For example, the elements of a contactless transmission application for mass transport must be able to communicate with the secure elements that manage Internet connection in order to allow the reloading of credit for the mass transport application via a server.
But these different applications are managed by different protocols, and elements from different applications may be powered with different power voltages, leading to conflict between the voltages used by the different elements and resulting in malfunctioning or even damage to the portable device.
There is therefore a need to offer a solution that makes it possible to avoid voltage conflicts between the constituent elements of the different applications.